Beech bark disease
Beech bark disease causes defects and mortality in American beech trees. In North America, this disease is tied to a combined effect of fungi and insect attackers. The introduced beech scale insect, Cryptococcus fagisuga, begins the cycle by feeding on the bark of a beech tree. Feeding activities of the scale insects create tiny wounds such that the tree becomes susceptible to two different species of Neonectria fungus: N. faginata and N. ditissima. Once the bark is wounded by the scale insect,…